JPS61215630A - Flexible vinyl chloride resin molding - Google Patents

Abstract

PURPOSE:To improve the surface nonmigratability of plasticizer, stainproofness, etc., of a flexible vinyl chloride resin molding, by forming a film of an acrylic resin specified in number-average MW, weight-average MW and MW distribution on the surface of the molding. CONSTITUTION:A vinyl chloride resin is mixed with a plasticizer (e.g., di-n-octyl phthalate), and the obtained mixture is formed into a sheet, film or the like. A film of an acrylic resin having a number-average MW >=30,000, a weight- average MW <=300,000 and a MW distribution (a ratio of a weight-average MW to a number-average MW) of 2-6 is formed on the surface of the above obtained flexible vinyl chloride resin molding. As said acrylic resin, a resin obtained by polymerizing at least 30wt% methyl methacrylate with a copolymerizable vinyl compound (e.g., acrylic acid) in a solution of a mixture of toluene and isopropyl alcohol can be suitably used.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a soft vinyl chloride P, 1# resin molded product.

More specifically, the present invention relates to a soft vinyl chloride resin molded product that is excellent in preventing surface migration of plasticizers and the like, and has stain-proofing and dust-proofing properties.

``Prior art'' In recent years, farmers cultivating useful plants have widely adopted methods of conserving or suppressing cultivation of useful plants in greenhouses or tunnels in order to improve acuity. It became so.

The covering materials for this greenhouse or tunnel include polyethylene film, ethylene-vinyl acetate, t[
Combined films, polyester films, polycarbonate films, hard and soft vinyl chloride resin films, glass, etc. are used. Among them, soft vinyl chloride resin film has a
It is widely used because it has the best overall light transmittance, heat retention, mechanical strength, durability, and workability.

On the other hand, based on past experience, for example, soft vinyl chloride M trees used for agricultural purposes are... Films are affected by the region and location where they are used, and after two years have passed since they were first used, the dustproof properties of the surface located outside of the tunnel will deteriorate significantly. It becomes unbearable to use.

As a method to eliminate the above drawbacks, for example,
28740, JP 50-28117, JP 56-99237, JP 56-99665
A method has been proposed in which a coating of acrylic P or resin having a specific composition is formed on one or both sides of a vinyl chloride resin film as a substrate. *Japanese Unexamined Patent Publication 1986-1970
No. 282 proposes a method of forming an acrylic resin film containing an ultraviolet absorber on the surface of a basic vinyl chloride M resin film.

Furthermore, JP-A No. 56-53070, JP-A No. 56-53070,
No. 70031, JP-A-57-163568, etc. propose a method of coating one surface of a vinyl chloride resin film as a substrate with a cationically polymerized energy ray-curable resin composition. ing.

[Problems to be Solved by the Invention] However, none of the above-mentioned methods can completely solve the problem of surface stain resistance or dust resistance of soft vinyl chloride resin films.

In other words, the method of coating the surface of a vinyl chloride resin film with acrylic P or resin, including those containing ultraviolet absorbers, is not suitable for use during periods of high outside temperature, especially in the summer, because the coating is mainly made of thermoplastic resin. Furthermore, it is difficult to completely prevent the additives contained in the base vinyl chloride resin film from migrating to the surface through the film and being washed away, making it difficult to prevent long-term use outdoors. remains a problem.

In addition, in the method of coating the surface of a vinyl chloride resin film with a cationically polymerized energy ray-curable resin composition, an epoxy resin composition is typically used as the coating material, but due to weather resistance deterioration, it is no longer used. However, this is also not suitable for achieving the purpose of imparting stain-proofing properties and dust-proofing properties to the base vinyl chloride resin film.

"Means for Solving the Problem" In view of the above situation, the present inventors have developed various additives blended into soft vinyl chloride resin molded products, which have excellent anti-staining properties, especially the ability to prevent plasticizers from migrating to the surface. In addition, various studies were conducted in order to provide a soft vinyl chloride resin molded product with a coating formed on the surface that has dustproof properties and maintains this effect.

As a result, even if the same acrylic P or resin is used, if it is an acrylic resin whose physical properties have been adjusted to a specific range, it can be applied to form a film that provides excellent stain resistance and dust resistance. The present invention was achieved based on the finding that a soft vinyl chloride resin molded article can be obtained.

In other words, the gist of the present invention is number-average molecules!
(hereinafter referred to as Mn) is 30,000 or more, the weight average molecular weight (hereinafter referred to as MI11) is 300,000 or less, and the molecular weight distribution (hereinafter referred to as Mw to Mn ratio; hereinafter Mw/
The present invention relates to a soft vinyl chloride resin molded article, characterized in that a coating of an acrylic resin having Mn (indicated by Mn) in the range of 2 to 6 is formed on the surface.

The present invention will be explained in more detail below.

In the present invention, the vinyl chloride resin that serves as the base of the soft vinyl chloride resin molded product includes monomers copolymerizable with vinyl chloride, including polyvinyl chloride and copolymers whose main component is vinyl chloride. Examples of the compound include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itafonic acid, acrylic acid, methacrylic acid, vinyl acetate, and the like. These vinyl chloride resins may be produced by any of conventionally known production methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization.

In order to impart flexibility to the vinyl chloride resin serving as the base, 20 to 60 parts by weight are added to 100 parts by weight of the resin.
Parts by weight of plasticizer are incorporated. By adjusting the blending amount of plasticizer within the above range, the desired soft vinyl chloride molded product can be produced.
It can provide excellent flexibility and mechanical properties.

As a plasticizer, for example, heptatalic acid derivatives such as di-n-octyl heptatalate, di-2-ethylhexyl heptatalate, dibenzyl heptatalate, diisodecyl heptatalate, didodecyl butanoate, diisodecyl heptatalate; dioctyl heptatalate; Isophthalic acid derivatives such as di-n-butyl adipate, dioctyl adipate; maleic acid derivatives such as di-n-butyl maleate; citric acid derivatives such as t'J-n-7'tiluntorate; motuputyl itaconate Itafonic acid derivatives such as; Oleic acid derivatives such as butyl oleate;
Other examples include ricinoleic acid derivatives such as ricinol/silica; others include triphrenor phosphate, epoxidized soybean oil, and epoxy resin plasticizers.

In addition to the plasticizer, a surfactant may be added to the vinyl chloride resin, if necessary. Specific examples include sorbitan ratulate, sorbitan myriritate, sorbitan palmitate, sorbitan stearate,
Sorbitan isostearate, curbitan behenate,
Sorbitan esters of fatty acids such as sorbitan oleate, sorbitan hydroxystearate, ethylene oxide adduct of sorbitan palmitate, ethylene oxide adduct of sorbitan stearate, polyoxyethylene nonylphenyl ethers, polyoxyethylene alkyl ethers, polyoxy Examples include ethylene fatty acid esters, shuboo esters, and cellulose ethers. These surfactants may be used alone or in combination of two or more.

In addition to the surfactant, the vinyl chloride P and resin may contain, if necessary, known resin additives that are usually blended into synthetic resins for molding, such as ultraviolet absorbers, light stabilizers, Antioxidants, heat stabilizers, lubricants, pigments, dyes, etc. can be added. However, in order to formulate a vinyl chloride resin compound composition for molding by blending plasticizers, surfactants, and other known resin additives, conventional blending and mixing techniques such as pump blender, Banbury, etc. A method using a mixer, super mixer or other compounding machine or mixer can be adopted.

There is no particular restriction on the shape of the soft vinyl chloride resin molded product of the present invention by molding the vinyl chloride resin blended composition, but sheet-like, Film, plate or tubular forms are suitable. These molding methods are appropriately selected from commonly used methods such as calender molding, extrusion molding, inlay molding, injection molding, and the like.

The acrylic resin used to form a film on the surface of the soft vinyl chloride resin molded article of the present invention preferably contains 30% by weight or more of methyl methacrylate, particularly preferably 50% by weight.
% by weight or more, and one or more vinyl compounds copolymerizable therewith. Examples of copolymerizable vinyl compounds in this case include methyl 7-acrylate, ethyl 7-acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, and 2-ethyl acrylate. C8 of ac-11 acid such as hexyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, stethyl acrylate
~C2□ alkyl esters; ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate , C8~ of methacrylic acid such as ste7lyl methacrylate
Alkyl esters of C2□; α, β-unsaturated carboxylic acid compounds such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, heptaconitic acid, crotonic acid; hydroxyalkyl acrylates, hydroxyfulkyl methacrylates, styrene, 7crylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acryl 7mide, methacryl 7mide, N-butoxy 7crylamide,
N-butoxy methacrylamide and the like can be mentioned.

Therefore, in the present invention, the acrylic resin has a number average molecular weight t (Mn), a weight average molecular weight (Mw), and a molecular weight distribution (Mw/Mn) within a specific range. is an essential requirement.

That is, the acrylic resin in the present invention has Mn of 30,000 or more, more preferably 40,000 or more, and Mw of 300.0 or more in terms of polystyrene measured by del permeation chromatography (GPC).
00 or less, more preferably 200.000 or less, and Mw/Mn is in the range of 2 to 6, preferably in the range of 2 to 4. In the case of acrylic resins with an Mn of 30.000 or less, the resulting film has reduced flexibility and easily cracks when bent, causing plasticizers in vinyl chloride resin molded products to deteriorate. The effect of preventing surface migration is lost. When Mw is 300,000 or more, the viscosity in the melted state or solution state becomes high, so that the coating and workability of vinyl chloride resin molded products are extremely poor, and it is difficult to use in practice. When Mw/Mn is 6.0 or more, the flexibility of the coating decreases or the performance of the coating becomes unstable, making it impractical.Those with Mw/Mn of 2 or less are expensive to manufacture ( Less economical.

Acrylic resins with the above physical properties can be produced using ordinary polymerization methods.
For example, Mu can be obtained by emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, etc.

In order to obtain an acrylic resin having a range of physical property values of Mw and M vs / M n, it is preferable to use a solution polymerization method. Among these, it is most preferable to use a mixed solvent of isopropyl alcohol and toluene as the solvent. In this case, the mixture of surrounding components Ill gold has a toluene/isopropyl alcohol volume ratio of 10:90.
and 60:40, preferably 20:80 and 50:50. If toluene is more than the above range,
Toluene may remain in the coating film or in the coated vinyl chloride resin molded product, causing odor, e.g.
Secondary defects such as blocking occur. On the other hand, when toluene is less than the above range, the M of the resulting acrylic resin is
Since n becomes small, it is not possible to obtain a material having the effect of preventing plasticizer migration.

In order to apply the above-mentioned acrylic resin to form a film on the surface of a soft vinyl chloride resin molded article, various known methods are applied depending on the shape of the molded article. For example, when forming a film in a solution state, coating methods such as doctor blade coating method, gravure roll coating method, air knife coating method, reverse roll coating method, dip coating method, curtain roll foot method, spray foot method, rod coating method, etc. method is used. Furthermore, when forming a single film using the acrylic resin without forming it into a solution, a coextrusion method, an extrusion coating method, an extrusion lamination method, and a lamination method are used.

When a coating method is used as a film forming method, there are, for example, natural drying methods, hot air drying methods, infrared drying methods, far infrared drying methods, etc., but if drying speed and safety are taken into account, Hot air drying methods are advantageous. In this case, the temperature condition is preferably in the range of 50 to 150°C, and the time is preferably selected in the range of 30 seconds to 5 minutes.

When applying an acrylic resin to the surface of a soft vinyl chloride resin molded product to form a film, the amount to be applied is as follows: If an undercoat is applied, the amount of the undercoat is set aside, and the amount after drying and solidification is calculated based on the application method. , 0.1g0, Ig/ra'', the effect of preventing the surface migration of the plasticizer in the soft vinyl chloride resin molded product is insufficient.
m'' or more, the amount of coating is too large, which is economically disadvantageous, and especially when the coated soft vinyl chloride resin molded product is a film-like structure, its mechanical strength may decrease. Therefore, usually 0.5g/-2
The most preferable range is 5 g/m. In addition, before coating the acrylic resin, the surface of the soft vinyl chloride resin molded product may be cleaned with alcohol or water, or subjected to plasma discharge treatment or corona discharge treatment. Alternatively, a pretreatment such as undercoating with another paint or primer may be performed to increase the affinity with the acrylic resin.

"Effects of the Invention" As described above, the present invention is a soft vinyl chloride resin molded product formed by forming an acrylic resin film with specific physical properties on the surface, and has the following particularly remarkable properties. (1) The soft vinyl chloride resin molded product according to the present invention has a coating of acrylic resin with specific physical properties on its surface, so that it can be used in the base resin. It is possible to suppress migration and exudation of blended additives such as plasticizers, surfactants, and liquid stabilizers onto the surface of the molded product. Therefore, it is possible to prevent contamination, dust, and dirt from adhering to the surface of molded products that use soft vinyl chloride resin as the base material, such as flooring materials, wall materials, desk mats, and cable covering materials, resulting in a beautiful appearance. can be maintained for a long period of time.

(2) If the soft vinyl chloride resin molded product is used as an agricultural covering material that is spread outdoors and requires sunlight transparency, the dustproof property will be maintained, so transparency will not be lost indefinitely. Gana (has a positive effect on the growth of plants).

"Examples" Next, the present invention will be described based on Examples, but the present invention is not limited to the following Examples unless the gist of the invention can be defined.

Examples 1 to 2, Comparative Examples 1 to 2 (1) Preparation of 1ft film of soft vinyl P and wood A film as an agricultural covering material was prepared by the following method.

Polyvinyl chloride (f'=1400) 100 parts by weight Dioctyl 7-talate (plasticizer) 50 Tricune norphosphate (plasticizer) 5 Epoxidized soybean oil (stabilizer) 1 Barium-zinc composite stabilizer ( Stabilizer) 1.5 #Barium stearate (lubricant) 0.211 Zinc stearate (lubricant) 0.4112-Hydroxybenzophenone (ultraviolet absorber) 0.611 Sorbitan palmitate fluoropylene oxide adduct (antifogging agent) 2.0# was weighed and mixed with a super mixer for 10 minutes.

The obtained resin composition was kneaded on a mill roll heated to 180°C, and a soft vinyl chloride resin film having a thickness of 0.15% was prepared using a calendar roll.

(2) Preparation of acrylic resin A: In a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a charging nozzle, 45.0 parts by weight of methyl methacrylate, 31.0 parts by weight of butyl methacrylate, and 2 -21.5 parts by weight of hydroxyethyl methacrylate, acrylic w
12.5 parts by weight, 1.0 parts by weight of benzoyl peroxide, 70 parts by weight of toluene, 16 parts by weight of isopropyl alcohol
0 parts by weight was charged, and while stirring in a nitrogen gas stream, 80 parts by weight was added.
The mixture was reacted at ℃ for 5 hours to obtain an acrylic resin solution. Tetrahydrofuran was added to the resin solution obtained in this way to make a solution with a resin concentration of 0.15%, and the solution was prepared using Waters GPC150C model and S hode as a column packing material.
Mn and Mw in terms of polystyrene were measured using x 80 M (manufactured by Showa Denko K.K., trade name). As a result, Mn=48000 Mm=152000Mw/Mn
=3.2.

This is referred to as acrylic resin (A).

B. Into the same reactor used in the example described in section A, 60 parts by weight of methyl methacrylate, 20 parts by weight of butyl 7-acrylate, and 2-human mixethyl methacrylate were added.
115 parts by weight, 1 part by weight of methacrylic R, 4 parts by weight of butyl acrylate, 1 part by weight of benzoyl peroxide,
70 parts by weight of toluene and 160 parts by weight of isopropyl alcohol were charged and reacted in the same manner as described in Section A to obtain an acrylic resin solution. This product was measured in the same manner as described in Section A, and the result was Mn=42000.
w= 137000. Mw/Mn=3,2.

This is referred to as acrylic resin (B).

In the same reactor used in the example described in section C0A,
The same types and amounts of monomers as in the example described in Section A were charged, and further 8 parts by weight of benzoyl peroxide and 230 parts by weight of isopropyl alcohol were charged and reacted in the same manner as described in Section A to obtain an acrylic resin. A solution was obtained.

This product was measured in the same manner as described in Section A, and the results were Mn=28000, Mw=221000, Mw/Mn
=7.9.

This is called acrylic 1.114 fat (C).

D. In the same reactor used in the example described in section A, B.
In addition, 8 parts by weight of benzoyl peroxide and 230 parts by weight of isopropyl alcohol were charged and reacted in the same manner as in the example described in Section A to obtain an acrylic resin composition. Thing S
I got the liquid. This product was measured in the same manner as described in Section A, and the results were Mn"25,000, Mw=215,000,
Mw/Mn=8.6.

This is referred to as acrylic resin (D).

(3) 7 Formation of an acrylic resin film on the surface of the ilm Isopropyl alcohol was added to each of the four types of acrylic resin solutions to adjust the concentration of the acrylic resin in the solution to 15%, and the soft chloride Each was applied to a vinyl resin film using a #5 percoater, and the applied film was held at 120° C. for 1 minute to scatter the solvent. The amount of coating on each film obtained was approximately 1.3g/102
Met.

(4) Evaluation method The properties of the four types of films obtained in item (3) above were evaluated using the following methods. The results are shown in Table 1.

■ Visibility Each film was cut to a width of 5 am and a length of 15 cm, and folded alternately at 2 emlifl intervals in a direction perpendicular to the length. In this state, a load of 2 kg was applied from above and the sample was left in a constant temperature bath kept at 15° C. for 24 hours. Then, the load was removed, the folds of the film were stretched out, and the appearance of the film was observed with the naked eye. The evaluation criteria for this test are as follows.

O: No change is observed in the film at the crease part Qx: Slight cracks are observed in the film at the crease part Δφ... Cracks are observed in the film at the crease part Recognized ×...Cracks are observed in the film at the creases, and the film has peeled off ■Plasticizer migration test Four types of films were tested at 10 cm x 10 am' each.
Cut into corners and apply a layer of thickness 0 to 5 on the surface where the coating is formed.
A +na+ polystyrene sheet was brought into close contact. In this state, a load of 2 kg was applied and the sample was left in a constant temperature bath maintained at 60° C. for 48 hours.

Then, the film was taken out from the thermostatic chamber, the load was removed, and the polystyrene film F was peeled off, and the weight loss of the four types of films was determined.

The lower the number, the less the plasticizer migrates from the film surface.

■ A pipe house (width: 3m, depth: 5111%, building height: 1.5m) was installed with four types of dust-proof films in a test field in Miegu-Shigun.
5n+, roof slope 30 degrees) with the coated surface facing the outside of the house, and a 2-year nut tension test was conducted from February 1980 to January 1988.

The film undergoing the stretching test was collected over time, and the light transmittance at a wavelength of 555 millimicrons was measured using a spectrophotometer (manufactured by Hitachi Seisakusho, Model EPS-20). The measurement results were displayed as follows.

◎・・・Light transmittance is 80% or more○・・・
・Those with a light transmittance in the range of 65 to 79% Δ...Those in the range of light transmittance of 45 to 64%×...Those in the range of light transmittance of less than 45% 1st
From Table 1, the following becomes clear.

(1) The soft vinyl chloride resin film (molded product) according to the present invention has excellent film flexibility compared to that of the comparative example,
Excellent bending and whitening resistance.

(2) In the soft vinyl chloride resin film of the present invention, the amount of liquid substances such as plasticizers blended in the base resin transferred to the surface is extremely small (and the surface of the molded product is not easily stained).

(3) The soft vinyl chloride resin film according to the present invention is
Even when used outdoors, the dustproof properties are extremely good, and the light transmittance remains at 65% or more even after being left outdoors for two years.

Applicant Mitsubishi Monsanto Chemical Vinyl Co., Ltd. Representative Patent Attorney Hase - (1 idiot)

Claims (2)

[Claims] (1) Number average molecular weight (hereinafter referred to as Mn) is 30,000 or more, weight average molecular weight (hereinafter referred to as Mw)
is 300,000 or less, and the molecular weight distribution (Mw vs. M
Refers to the n ratio. 1. A soft vinyl chloride resin molded article, characterized in that an acrylic resin coating having a Mw/Mn (hereinafter referred to as Mw/Mn) in the range of 2 to 6 is formed on the surface. (2) The acrylic resin is synthesized in the presence of a polymerization solution consisting of a mixture of toluene and isopropyl alcohol.
) The soft vinyl chloride resin molded product described in item 2.